A biometric recognition technology is suggested instead of a fingerprint recognition technology in fields such as access control, assiduity management, an integrated building management system, an automatic teller machine, a computer security, an electronic commerce authentication, an airport information system or the like. Particularly, a face recognition technology is used for recognizing a face of a person by using face information indicating unique characteristics of the person.
A typical face recognition apparatus is configured such that a user authenticates a person while monitoring a face of the person which has been captured on a screen. An apparatus capable of capturing an image by using only a visible light can work well under a comparatively bright environment with visible light, but outputs a black image in a dark environment without visible light. A typical illuminometer does not have such problem, but causes malfunction when bright light turns dark or when the light is shielded by a user.